Bluetooth: Fix redundant encryption when receiving Security Request

If we're already encrypted with a good enough LTK we should just ignore
an incoming SMP Security Request. The code was already taking care of
this in the smp_conn_security function before calling smp_ltk_encrypt
but failed to do the same in smp_cmd_security_req. This patch fixes the
issue by moving up the smp_sufficient_security function and using it in
the Security Request handler before trying to request encryption.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 35f57090ddd0f83f74b440c040df66e2111c3fee..6ce7785a2708fb4cf95d86459289203a178bf1b2 100644 (file)
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -859,6 +859,17 @@ static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level)
        return true;
 }
 
+bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level)
+{
+       if (sec_level == BT_SECURITY_LOW)
+               return true;
+
+       if (hcon->sec_level >= sec_level)
+               return true;
+
+       return false;
+}
+
 static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
 {
        struct smp_cmd_security_req *rp = (void *) skb->data;
@@ -876,6 +887,9 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
                return SMP_CMD_NOTSUPP;
 
        sec_level = authreq_to_seclevel(rp->auth_req);
+       if (smp_sufficient_security(hcon, sec_level))
+               return 0;
+
        if (sec_level > hcon->pending_sec_level)
                hcon->pending_sec_level = sec_level;
 
@@ -904,17 +918,6 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
        return 0;
 }
 
-bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level)
-{
-       if (sec_level == BT_SECURITY_LOW)
-               return true;
-
-       if (hcon->sec_level >= sec_level)
-               return true;
-
-       return false;
-}
-
 int smp_conn_security(struct hci_conn *hcon, __u8 sec_level)
 {
        struct l2cap_conn *conn = hcon->l2cap_data;